In institutional settings such as hospitals, meals for patients are typically served at the patient's room. The food is prepared at a remote food preparation area, such as a hospital kitchen, and then transported to the patient's room for consumption. At the food preparation area, various hot and cold food items are heated or chilled to an optimum temperature and then assembled on trays for serving. When large numbers of meals are to be prepared and served, food palatability often suffers as the time between preparation and service results in food being served at less than optimum temperatures.
To maintain foods at optimal serving temperature during transport, many institutional food preparers utilize a food servicing cart that is insulated to keep cold foods cold and hot foods hot. Such food servicing carts have evolved from what was once a very simple cart design to carts that now feature on-board refrigeration and rethermalization systems. The earliest food servicing carts were heavily insulated with separate hot and cold food storage compartments. Hot and cold food items would be loaded into respective compartments at a food preparation area, and the loaded carts would then be wheeled to various serving areas where hot and cold food items would be assembled onto one tray and served. While this approach helped to maintain food temperatures at acceptable levels during transport, it did not offer a complete solution. Assembly of meals at the serving areas resulted in significant food temperature degradation, especially when many trays had to be assembled at one serving area.
Later approaches included the development of trays onto which meals were preassembled and loaded onto shelves in the carts. The assembled food trays were then kept in a refrigerated environment. At a desired serving time, hot food items were rethermalized, or heated to a serving temperature, while cold food items remained isolated from the rethermalization heat. In one design, a refrigerated environment was provided by a separate refrigeration unit into which the cart was stored. The cart was electrically docked with the refrigeration unit and, at a desired serving time, a timer on the refrigeration unit controlled the duration of time that electrical heaters on the cart were energized to conductively warm hot food items. After rethermalization was complete, the electrical heaters on the cart were used to maintain foods in a rethermalized state within the refrigerated environment. A major drawback of this approach was inefficiency. In addition to refrigerating the food on the inside of the cart, the refrigeration unit had to expend additional energy to refrigerate the entire outer surface of the cart. Further, keeping foods hot within a refrigerated environment also increases inefficiency.
Another approach to providing a refrigerated environment for the cart is to include all necessary refrigeration and rethermalization elements on the cart itself. A refrigerator provides refrigeration to the cart, and rethermalization of food items is accomplished by individual electrical heaters positioned on shelves within the cart. Food trays are designed and loaded so that foods that are to be rethermalized are positioned adjacent one of the shelf heaters for conductive heat transfer from the heating elements, through the trays, and into the food items. Cold food items are positioned on the trays remote to the heaters. Electrical power for the cart is provided by a power cord that is plugged into a wall receptacle. An on-board computer, programmed with various rethermalization profiles, controls refrigeration and rethermalization of food items in accordance with a selected rethermalization program. This type of system, although flexible and effective, results in a food servicing cart that is large and bulky. As with other approaches, there is also inefficiency resulting from maintaining rethermalized foods within a refrigerated environment.
What is needed, therefore, is a versatile and efficient food refrigeration and rethermalization system for a food storage cart in which the cart can be easily separated from the refrigeration and rethermalization means to enhance transportation of the cart to a food service area.